Changes in bovine milk bacterial microbiome from healthy and subclinical mastitis affected animals of the Girolando, Gyr, Guzera, and Holstein breeds / Cambios en el microbioma bacteriano de la leche bovina de animales sanos y afectados por mastitis subclínica de las razas Girolando, Gyr, Guzera y Holstein

Raw milk samples were collected from 200 dairy cows belonging to Girolando 1/2, Gyr, Guzera, and Holstein breeds, and the bacterial diversity was explored using 16S rRNA amplicon sequencing. SCC analysis showed that 69 animals were classified as affected with subclinical mastitis. The milk bacterial microbiome was dominated by Firmicutes, Proteobacteria, and Actinobacteria, with an increase of Firmicutes in animals with subclinical mastitis and Proteobacteria in healthy animals. At the family and genus level, the milk bacterial microbiome was dominated by Staphylococcus, Acinetobacter, Pseudomonas, members of the family Enterobacteriaceae, Lactococcus, Aerococcus, members of the family Rhizobiaceae, Anaerobacillus, Streptococcus, members of the family Intrasporangiaceae, members of the family Planococcaceae, Corynebacterium, Nocardioides, and Chryseobacterium. Significant differences in alpha and beta diversity analysis suggest an effect of udder health status and breed on the composition of raw bovine milk microbiota. LEfSe analysis showed 45 and 51 discriminative taxonomic biomarkers associated with udder health status and with one of the four breeds respectively, suggesting an effect of subclinical mastitis and breed on the microbiota of milk in cattle.(AU)

Changes in bovine milk bacterial microbiome from healthy and subclinical mastitis affected animals of the Girolando, Gyr, Guzera, and Holstein breeds.

Raw milk samples were collected from 200 dairy cows belonging to Girolando 1/2, Gyr, Guzera, and Holstein breeds, and the bacterial diversity was explored using 16S rRNA amplicon sequencing. SCC analysis showed that 69 animals were classified as affected with subclinical mastitis. The milk bacterial microbiome was dominated by Firmicutes, Proteobacteria, and Actinobacteria, with an increase of Firmicutes in animals with subclinical mastitis and Proteobacteria in healthy animals. At the family and genus level, the milk bacterial microbiome was dominated by Staphylococcus, Acinetobacter, Pseudomonas, members of the family Enterobacteriaceae, Lactococcus, Aerococcus, members of the family Rhizobiaceae, Anaerobacillus, Streptococcus, members of the family Intrasporangiaceae, members of the family Planococcaceae, Corynebacterium, Nocardioides, and Chryseobacterium. Significant differences in alpha and beta diversity analysis suggest an effect of udder health status and breed on the composition of raw bovine milk microbiota. LEfSe analysis showed 45 and 51 discriminative taxonomic biomarkers associated with udder health status and with one of the four breeds respectively, suggesting an effect of subclinical mastitis and breed on the microbiota of milk in cattle.

Prospecting of potentially probiotic lactic acid bacteria from bovine mammary ecosystem: imminent partners from bacteriotherapy against bovine mastitis / Prospección de bacterias ácido lácticas potencialmente probióticas del ecosistema mamario bovino: socios inminentes de la bacterioterapia contra la mastitis bovina

Mastitis is one of the most important causes of loss of cattle production, burdening producers due to the increased cost of milk production and decreased herd productivity. The development of alternative methods for the treatment and prevention of mastitis other than traditional chemical antibiotic therapy needs to be implemented to meet international pressures to reduce the use of these drugs and promote the elimination of multiresistant microbial strains from the environment. Treatment with probiotic bacteria or yeast strains offers a possible strategy for the control of mastitis. The objective of this work was to isolate, identify, and characterize lactic bacteria from milk and the intramammary duct of Gyr, Guzerat, Girolando 1/2, and Holstein cattle breeds from Brazil. Samples of 115 cows were taken, a total of 192 bacteria isolates belonging to 30 species were obtained, and 81 were selected to evaluate their probiotic potential in in vitro characterization tests. In general, bacteria isolated from the mammary gland have low autoaggregation, cell surface hydrophobicity, and co-aggregation with mastitis etiological bacteria Staphylococcus aureus and Escherichia coli. Also, they have biofilm assembly capacity, inability to produce exopolysaccharides, high production of H2O2, and strong antagonism against mastitis pathogens. Ten lactic bacteria isolates were used in co-culture with human MDA-MB-231 breast epithelial cells to assess their adhesion capacity and impairment of the S. aureus invasion. Our results, therefore, contribute to the future production of new prevention and treatment tools for bovine mastitis.(AU)

Prospecting of potentially probiotic lactic acid bacteria from bovine mammary ecosystem: imminent partners from bacteriotherapy against bovine mastitis.

Mastitis is one of the most important causes of loss of cattle production, burdening producers due to the increased cost of milk production and decreased herd productivity. The development of alternative methods for the treatment and prevention of mastitis other than traditional chemical antibiotic therapy needs to be implemented to meet international pressures to reduce the use of these drugs and promote the elimination of multiresistant microbial strains from the environment. Treatment with probiotic bacteria or yeast strains offers a possible strategy for the control of mastitis. The objective of this work was to isolate, identify, and characterize lactic bacteria from milk and the intramammary duct of Gyr, Guzerat, Girolando 1/2, and Holstein cattle breeds from Brazil. Samples of 115 cows were taken, a total of 192 bacteria isolates belonging to 30 species were obtained, and 81 were selected to evaluate their probiotic potential in in vitro characterization tests. In general, bacteria isolated from the mammary gland have low autoaggregation, cell surface hydrophobicity, and co-aggregation with mastitis etiological bacteria Staphylococcus aureus and Escherichia coli. Also, they have biofilm assembly capacity, inability to produce exopolysaccharides, high production of H2O2, and strong antagonism against mastitis pathogens. Ten lactic bacteria isolates were used in co-culture with human MDA-MB-231 breast epithelial cells to assess their adhesion capacity and impairment of the S. aureus invasion. Our results, therefore, contribute to the future production of new prevention and treatment tools for bovine mastitis.

Effect of exogenous amylase on lactation performance of dairy cows fed a high-starch diet.

Exogenous amylase supplementation can increase starch and fiber digestibility in lactating dairy cows. We evaluated the effect of exogenous amylase supplementation on diets with high starch concentration (32% of dry matter). Twenty-eight Holstein cows (171 ± 80 d in milk, 4 primiparous) received a standard diet for 14 d and then a treatment for 63 d, in a covariate-adjusted randomized block design with repeated measures over time. Treatments were amylase [0.5 g of Ronozyme RumiStar (DSM Nutritional Products, Basel, Switzerland) per kg of total mixed ration dry matter] or control. The diets contained (% of dry matter): 39.4% corn silage, 11.2% rehydrated and ensiled mature corn grain, and 11.7% finely ground mature corn. Amylase increased milk yield (32.3 vs. 33.0 kg/d) and reduced dry matter intake (20.7 vs. 19.7 kg/d), increasing feed efficiency (1.52 vs. 1.63). Amylase also increased milk lactose synthesis (1.49 vs. 1.56 kg/d) and plasma glucose concentration (59.3 vs. 68.6 mg/dL). Secretions of milk fat and protein did not differ. Although milk urea N did not differ, amylase reduced the concentration of urea N in blood, suggesting an increase in ruminal starch degradation. However, the total-tract apparent digestibility of starch (96.3% of intake) and neutral detergent fiber (44.4% of intake), ruminal fermentation profile, and microbial yield estimated by urinary allantoin excretion did not differ. Cows fed amylase sorted in favor of long feed particles and against short particles, had shorter chewing activity (780 vs. 699 min/d), and had fewer meals per day (11.5 vs. 9.7). Amylase improved the feed efficiency of lactating cows fed a high-starch diet; the enzyme increased milk yield and reduced intake.